Vibratory Diagnosis by Finite Element Model Updating and Operational Modal Analysis

Guillaume Gautier (1) , Roger Serra (1) , Jean-Mathieu Mencik (1)

1 LMR - Laboratoire de Mécanique et de Rhéologie

In this paper, a subspace fitting method is proposed to update, in the time domain, the finite element model of a rotating machine. The procedure is achieved by minimizing an error norm, leading to the comparison between experimental and theoretical observability matrices. Experimental observability matrix is obtained through a MOESP subspace identification algorithm, by projecting the output signal onto some appropriate subspaces, resulting in a cancellation of input excitations and noises. The theoretical observability matrix is obtained from modal parameters of a finite element model of the structure. The minimization procedure is carried out through a Gauss-Newton algorithm. The method is applied to determine the foundation stiffness of an experimental rotating machine subject to a random noise.

Mots clés: Subspace fitting; Operational Modal Analysis; Finite Elements Model Updating; Vibratory Diagnosis; Rotating machine

Domaines: Vibrations [physics.class-ph]; Vibrations [physics.class-ph]

Guillaume Gautier, Roger Serra, Jean-Mathieu Mencik. Vibratory Diagnosis by Finite Element Model Updating and Operational Modal Analysis. Mechanics & Industry, 2013, Volume 14 (Issue 02), pp.145-149. ⟨10.1051/2013055⟩. ⟨hal-00819616⟩